Retainer for bucket teeth



Feb. 27, 1962 c. M. TowNE 3,022,586

RETAINER FOR BUCKET TEETH Filed May 18, 1959 2 Sheets-Sheet 1 Feb. 27, 1962 Filed May 18, 1959 C. M. TOWNE RETAINER FOR BUCKET TEETH 2 Sheets-Sheet 2 lignite States Patent @flee 3,622,586 RETAINER FR-BUCKET TEETl-I t ClaudeV M. Towne, Watertown, Wis', assigner to. General Metals Corporation, a corporation or Delaware Filed May 1S, 12359, Ser. No. 813,?95

' S Claims. (Cl. 257-442) This invention relates to a retainer for digging teeth on earth moving machinery and the like, and more particularly to an all-metal retaining pin for holding replaceable tooth points on base members attached to a digging bucket,

Many earth digging machines employ buckets equipped with teeth which aid in biting into the soil, roch or debris. The teeth are generally replaceable since the use of the machinery wears the teeth. ln the past it has been usual to equip a digging bucket with adaptors or base members having a nose over which a replaceable tooth cap or point could be placed. The tooth points would receive the brunt of wear during use and when they became sutilciently dull, they were removed and replaced by new points. This has been conveniently done by using retaining pins which extend through aligned openings in the tooth point housing and the adaptor or supporting base. The present invention has to d with a particularly improved retaining pin for this purpose.

lt is the primary object of this invention to provide a new and improved all-metal retaining pin of thecharacter described.

Another object of the invention is to provide a new-allmetal pin capable of taking up a relatively large movement of a replaceable tooth point longitudinally of its supporting base and still maintain the tooth point tight upon the base.

Another object is to provide an all-metal retaining pin which can be made in relatively short lengths yet permit considerable movement longitudinally of the tooth point. er objects, features and advantages of the present invention will be apparent from the following description of a preferred embodiment illustrated in the accompanying drawings, in which:

FGURE l is a sideV elevational view, partially broken away, or a replaceable tooth point, with the pin of this tooth point and base and retaining pin, taken substan-V tially along the lines 2 2 in lilGUlE l;

lFlG-URE 3 is a sectional view through the structure of l-"GURE l, taken substantially along the line 3 3 therein;

ClGURE 4 is ka side elevational view of the retaining pin of this invention;

GURE 5 is atop plan view of the piu, .and

lilGURE 6 is an end view of the pin. .All of FlG- URES 4, 5 and 6 are enlarged for clarity of illustration.

Earth digging machinery or" many types use buckets or bhadesV equipped with digging teeth. Trenching machinery of the rotary bucl-:et type, various types of hoes, and cranes equipped with digging buckets all have, in the past, used replaceable teeth.` The invention is applicable to any earth digging or moving machinery which use teeth which must be replaced from time to time.

Referring particularly to FIGURES 1 through 3, a tooth supporting base 7 is Vfragrnentarily shown as having front or forwardly extending nose S which is equipped with an upper surface 9 and a lower surface l, which converge toward each other and are joined by a slightly curved end ll'forrning the nose upon which the replaceable point is to be seated. The nose portion is thus z Iatented` Feb. 27, 1962 2 (not shown) which is either integrally or otherwise attached to the front lip of a bucket plate or an arm constituting the support for the. digging tooth` vThe replaceable tooth point generally employs aspecially hardened plate-like top portion 14, 'which may be sharpened on its underside adjacent its end 16 to provide the tooth with a sharpened or relatively bluntly sharpcned outer end. The plate 14 extends over the length of the tooth point. It is attached to the tapered nose 8 by means of a housing generally indicated 17, welded or otherwise attached to the underside of the plate. The housing is best seen in FIGURES 1 and 3 as having side walls 18 and 19 and a bottom wall 20. These walls are welded, as by the weld 21 at the forward end of the bottorn wall to the underside of the plate, and form a tapered socket to lit over the nose 8. The underside of the plate 1d lits in face to face contact with the upper surface 9 of the tapered nose. The inner surface of the wall of the housing likewise fits in face to face contact with the lower surface lo of the tapered nose. The tooth is thus wedged onto the adaptor nose.

The means employed to secure the tooth in place should be capable of not only holding the tooth point against falling oil, but should hold the tooth point tightly upon the tapered nose of the adaptor. The retaining pin of this invention is particularly adapted to maintain the tooth point tight and to takerup any expansion of the housing which might allow the tooth point to move further on to the supporting noseot the adaptor. The connection is provided in this instance by use of aligned openings in the adaptor nose and in the side walls of the housing ofthe replaceable tooth point. Referring to FIGURES l through 3, the opening in the adaptor is shown as an oblong shaped, straight through passage 22. The openings in the side walls of the housing are two intersecting circular openings, 23 and 24, as shown in FIGURE 1, forming one opening herein designated as 25 in the wall 19, and a similar opening 26 in the wall 18. The openings in the tooth point housing are generally oiset toward the end of the tooth a slight amount relative to the opening 22 through the adaptor nose. The accuracy of location of thel openings relative to each other is subject to some variation due to inaccuracies in manufacture of the adaptors. In instances where the adaptor is a casting and the opening 22 a cored opening, some inaccuracies will result. l

The retaining tooth as herein shown has a base niember 27 and a pair of spring lingers 28 and 29. The latter bear on the cap to urge the replaceable tooth point toward a seating position on the adaptor. The base 27 of the pin rests solely against the adaptor and bears in the opening 22 to oppose the urging of the ngers.

The form of the retaining pin is particularly shown in FIGURES 4 through 6. The pin is formed ot spring steel given heat and quenching treatments to make the lingers particularly ductile. Machining operations upon a metal stock, which is slightly obround to start with, produce the lingers 2S and 29 rornfthe solid pin stock. A saw cut from the ends of the stock inwardly form the at surfaces 3@ andt on the base portion of the pin; Ordinarily, the angle of this cut from the horizontal length of the pin may range through a number of degrees of the order of IS-iil, in order to give the resilient fingers-2? and 29 a thicker base than tip. Thenger portions areintendedV to flex in order to take up any movement of the tooth point on to the adaptor nose as well as to ex during insertion or extraction of the pin.

The base portion is provided with outwardly extending heads 32 and 33 having generally gentle sloped portions v34 and'35, facing the end surfaces 36 and 37 respectively of .the base; These sloping surfaces arepgenerally used to guide the pin into the ah'gned openings during inseition of Y 3 the pin. Two rather crescent-shaped surfaces, 38 and 39 on the inner side of the heads, are given about a l degree taper to a transverse plane through the pin. These crescent-shaped surfaces are intended to hold the pin .longitudinally relative to the adaptor Yby gripping the sides of the adaptor Vadjacent the opening 22 through theV adaptor nose. The slight taper of the surfaces acts as a wedge plane to cam'the head into the opening as the pin is driven out of position. Y.

The linger portions which will eX relative to the base vportion are each provided with an outer end portion 40 and 41 sloped downwardly from the crests 42 and 43 which arefurthest from the base portion 27. The outer surface of the bent down end portions is generally given a suiiicient Yangle to the longitudinal extent of the pin to insure that the pin can be urged into the aligned openings of the point and adaptor nose. The outer end of the Vringer portions is much thinner than the inner portion attached to the center of the base portion. The exibility of the ends is thus slightly greater than that of the base of the lingers.

Referring particularly to FIGURE 2, it will be noted that the crests 42 and 43 of the linger portions bear solely against Ythe edge of the openings 25 and 26 inthe vhousing` of the replaceable tooth point. When in position, the fingers are exed so that they resiliently urge the tooth Vpoint onto the adaptor. The base portion 27 of the pin Ahas its shoulders so spaced that they gripthe opening through n the adaptor nose. nally in position, Y n

When the pin is to belremoved from the position shown holds the 'pin longitudi- Vin FIGURE 2, a ball peen hammer may be used to strike either end surfaces 36 or 37 to start the pin on its inward direction. A drift pin may be used to complete the driving ofthe pin` out of the opening- The pin is intended for reuse and thus when a new point is placed on the adaptor, the pin may be reinserted.` Initially, the sloping surface such as 35 on one end or the base portion and the sloping outer surface of the end portion 41 together cam the relatively movable parts of the lingers and base together to Ydecrease the overall lateral width of the pin, allowing its passage into the openings. Once the shoulders snap over Vthe edges of the opening in the adaptor nose, the pin will y be retained in position, asV shown in FIGURE 2.

Generally, the bifurcated end all-metal pin, as shown in the drawings, may Vbe` conveniently used for relatively small sizes of replaceable tooth points*A Caps which are abouti-2V: inches widev are used with pins of this type.

`An advantage of this all-metal pin isrthat the ngers Yare capable of taking up considerable lateral movement of the bore even though the over all length of the pin is relatively short. rThe resiliency of the inger portions, even in short lengths, Vis such as to allow substantial closing of with aligned openings for register with a bore through a Y supporting base, a retainer for securing the replaceable cap on the. base, comprising: a spring steel pin of elongate form having a base portion with end surfaces for receiving end delivered blows to insert and remove the pin from said bore and aligned openings and a pair of integral pin end portions secured to the base portion centrally thereof each offset laterally relative to the base portion of the pin to permit resilient liexing of the pin end portions toward the base portion, said pin end portions having wedge surfaces for exing said portions upon insertion of the pin endwise into said cap openings and supporting base bore with said end portions bearing only against said cap and exerting pressure against said cap in opposition to said base portion bearing only against said base so that exure of the pin end portions resiliently holds the cap on said base. Y

2. In an earth digging tooth having a replaceable cap with aligned openings for register with a bore through a supporting base, a retainer for securing the replaceable cap on the base, comprising: a spring steel pin of elongate form having a base portion and a pair of resiliently bendable linger portions integrally joined to the base portion centrally thereof, said finger portions having their end portions spaced from the base portion when unilexed, wedge surfaces on said inger portions at the ends thereof and on said base'portion at the ends thereof for iiexing the lingers toward the oase portion upon endwise insertion of the pin in said bore and openings, said iinger portions having a length and being positioned to engage only said cap in said openings whenV the pin is seated with said base portion Vsaid base portion having alength substantially equal to the iinger portions and engaging only said supporting base in said bore so that the resilient finger portions yieldingly urge the cap onto the'supporting base.

3. In an earth digging replaceable tooth cap having Valigned side openings upon a base having a cross bore, a

retainer for securing the replaceable cap on the base, comprising: a spring steel elongated pin having a base and a finger member attachedrto the base and resiliently yieldable relative to the base, said base and finger member having a width when the latter is not 1flexed greater than the width of said cross bore and openings, a wedge surface'formed on said base and finger member for engaging the replaceable tooth cap within.Y said side openings Yand said base in said cross bore permitting springing of the pin within the adapter bore by endwise insertion, and a shoulder on said base of the pin at the base of said wedge surface for retaining the Vpin within the adapter bore against accidental removal, said pin constantly resilientiy urging the cap'on said base when the pin is sprung in the cross bore and cap side openings with the base engaging in said bore and the end or" said linger engaging said cap in said opening said end of'said iinger lying generally in a common plane with Vrespect to the base.

4. ln an earth digging tooth having a replaceable cap with aligned openings for register with a bore through a supporting base, a retainer for securing the replaceable cap on the base, comprising; a spring steel pin of elongate orm having a base portion and a pair of resiliently bendable nger portions integrally Vjoined to the base por- `tion centrally thereof, said iinger portions having their end portions spaced from the base portion when uniiexed, wedge surfaces on said finger portions at the ends thereof and on said base portion at the ends thereof for flexing the fingers toward the base portion upon endwise insertion of the pin in said bore and openings, said finger portions having a length and being positioned to engage only said cap in said openings when the pin is seated vwith said base portionengaging only said supporting base in said bore so that the resilient nger portions yieldingly urge the cap onto the supporting base, said base portion being Vprovided with an end surface generally normal to the eX- tent of said pin for receiving end delivered blows to insert and remove the pin from said bore and aligned openings and said finger portions being tapered in section from said joining with said base portion toward their end portions. f

' 5. In an earth digging tooth having a replaceable cap with aligned openings for register with a bore through a `supporting base, a retainer for securing the replaceable capron the base, comprising: a unitary spring steel pin having a base portion extending over the length of the pin and having end surfaces for receiving end blows selectively for inserting and removing the pin from said aligned openings and bore -by endwise movement of the pin relative to the openings and the bore, a pair of resilient iinger portions integral with said base portion, secured thereto intermediate the ends thereof and extending generally lengthwise of the base, said finger portions having outer end portions spaced laterally from and extending toward said base portion forming an outwardly facing wedge surface for wedging the pin in said aligned openings and bore upon endwise insertion of the pin therein, said wedge surfaces being spaced laterally from said base portion for engaging only said cap in said openings therein and constantly urging the cap onto said supporting base when said pin base portion is in engagement with thev vsupporting base.

References Cited in the file of this patent UNITED STATES PATENTS Armstrong July 16, Rose June 18, Troendly June 16, Seal July 29, Churchill Sept, 8, Wilson Dec. 1, Daniels et a1 Apr. 13, Launder Aug. 31, Krekeler Apr. 10, Opsahl May 17,

FOREIGN PATENTS France June 20, 

